Patent Document 1 discloses a method for controlling undesired plants, which comprises applying dimethenamid and at least one other herbicide selected from amino acid synthesis inhibitors to the undesired plants.
Patent Document 2 discloses a synergistic herbicidal composition comprising a 3-heterocyclyl-substituted benzoyl derivative and a specific herbicide.
However, either of the above Patent Documents does not disclose a specific combination of compound A, compound B and compound C which are herbicidally active ingredients of the present invention, and does not specifically disclose a remarkable synergistic effect obtained by the combination.